/* ============================================
   Compreso - Unicode Text Compressor
   Modern Minimal Stylesheet
   ============================================ */

/* ---- CSS Custom Properties (Light Theme) ---- */
:root {
  --bg: #ffffff;
  --text: #1a1a2e;
  --accent: #6c63ff;
  --card-bg: #f5f5ff;
  --border: #e0e0f0;
  --highlight: #fff3cd;
  --success: #28a745;
  --warning: #ffc107;

  --radius-lg: 12px;
  --radius-sm: 8px;
  --radius-xs: 4px;
  --radius-pill: 9999px;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);

  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;

  --font-body: 'Noto Sans', sans-serif;
  --font-mono: 'Noto Sans', monospace;

  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
}

/* ---- Dark Theme ---- */
[data-theme="dark"] {
  --bg: #0f0f23;
  --text: #e0e0f0;
  --accent: #7c73ff;
  --card-bg: #1a1a2e;
  --border: #2a2a4e;
  --highlight: #4a4000;
  --success: #34ce57;
  --warning: #ffcd39;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
}

/* ---- Light Theme (explicit) ---- */
[data-theme="light"] {
  --bg: #ffffff;
  --text: #1a1a2e;
  --accent: #6c63ff;
  --card-bg: #f5f5ff;
  --border: #e0e0f0;
  --highlight: #fff3cd;
  --success: #28a745;
  --warning: #ffc107;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
}

/* ---- System Preference Fallback ---- */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --bg: #0f0f23;
    --text: #e0e0f0;
    --accent: #7c73ff;
    --card-bg: #1a1a2e;
    --border: #2a2a4e;
    --highlight: #4a4000;
    --success: #34ce57;
    --warning: #ffcd39;

    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  }
}

/* ---- Global Reset & Base ---- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  transition: background var(--transition-base), color var(--transition-base);
}

/* ---- Focus Styles ---- */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---- Screen Reader Only ---- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ============================================
   HEADER
   ============================================ */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg) var(--spacing-xl);
  max-width: 1200px;
  margin: 0 auto;
}

header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--accent);
}

#theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--card-bg);
  color: var(--text);
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
}

#theme-toggle:hover {
  background: var(--border);
  transform: scale(1.05);
}

#theme-toggle:active {
  transform: scale(0.95);
}

#theme-toggle svg {
  width: 22px;
  height: 22px;
  transition: opacity var(--transition-base), transform var(--transition-base);
}

/* Show/hide icons based on theme */
[data-theme="dark"] #theme-toggle .sun-icon {
  opacity: 1;
  transform: rotate(0deg);
  position: static;
}

[data-theme="dark"] #theme-toggle .moon-icon {
  opacity: 0;
  transform: rotate(90deg);
  position: absolute;
}

#theme-toggle .sun-icon {
  opacity: 0;
  transform: rotate(-90deg);
  position: absolute;
}

#theme-toggle .moon-icon {
  opacity: 1;
  transform: rotate(0deg);
  position: static;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) #theme-toggle .sun-icon {
    opacity: 1;
    transform: rotate(0deg);
    position: static;
  }

  :root:not([data-theme]) #theme-toggle .moon-icon {
    opacity: 0;
    transform: rotate(90deg);
    position: absolute;
  }
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.header-controls .char-limit-controls {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.header-controls .char-limit-controls label {
  font-size: 14px;
  color: var(--text);
  opacity: 0.7;
}

.header-controls .char-limit-controls input {
  width: 80px;
  padding: 4px 8px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg);
  color: var(--text);
}

/* ============================================
   MAIN LAYOUT
   ============================================ */
main {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-lg);
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-xl) var(--spacing-xl);
}

/* ---- Editor Section (Two Column) ---- */
#editor.two-column {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-lg);
}

.column {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

/* ---- Textareas ---- */
textarea#input-text {
  width: 100%;
  min-height: 200px;
  max-height: 600px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  padding: var(--spacing-md);
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  line-height: 1.7;
  background: var(--bg);
  color: var(--text);
  resize: vertical;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-base);
}

textarea#input-text::placeholder {
  color: var(--text);
  opacity: 0.4;
}

textarea#input-text:hover {
  border-color: var(--accent);
}

textarea#input-text:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.15);
}

/* Custom scrollbar for textarea */
textarea#input-text::-webkit-scrollbar {
  width: 8px;
}

textarea#input-text::-webkit-scrollbar-track {
  background: transparent;
}

textarea#input-text::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}

textarea#input-text::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}

/* Firefox */
textarea#input-text {
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

/* ---- Output Area ---- */
.output-wrapper {
    position: relative;
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 200px;
    max-height: 600px;
    overflow: hidden;
}

#output-text {
    width: 100%;
    flex: 1;
    overflow: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    padding: var(--spacing-md);
    font-family: var(--font-mono);
    font-size: 0.9375rem;
    line-height: 1.7;
    background: var(--card-bg);
    color: var(--text);
    white-space: pre-wrap;
    word-break: break-word;
    overflow-wrap: break-word;
    transition: background var(--transition-base), border-color var(--transition-fast);
    resize: none;
}

#copy-icon {
    position: absolute;
    bottom: 8px;
    right: 8px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 6px;
    cursor: pointer;
    color: var(--text-secondary);
    opacity: 0.6;
    transition: opacity 0.2s, background 0.2s;
    z-index: 10;
}

#copy-icon:hover {
    opacity: 1;
    background: var(--accent);
    color: white;
}

#copy-icon svg {
    display: block;
}

/* ============================================
   STATS BAR
   ============================================ */
#stats-bar {
  grid-column: 1 / -1;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  padding: var(--spacing-md);
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  transition: background var(--transition-base), border-color var(--transition-base);
}

.progress-container {
  height: 8px;
  background: var(--border);
  border-radius: var(--radius-xs);
  overflow: hidden;
}

#compression-progress {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), #9b94ff);
  border-radius: var(--radius-xs);
  transition: width var(--transition-base);
}

#stats-text {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text);
  opacity: 0.8;
  text-align: center;
}

/* ============================================
   CATEGORIES SECTION
   ============================================ */
#categories {
  grid-column: 1 / -1;
  padding-top: var(--spacing-md);
}

#categories h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  color: var(--text);
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-md);
}

/* ---- Category Card ---- */
.category-card {
  position: relative;
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-base), border-color var(--transition-fast);
  cursor: pointer;
}

.category-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}

.category-card:active {
  transform: translateY(-1px);
}

/* Hide the actual checkbox */
.category-toggle {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
  pointer-events: none;
}

/* Card label layout */
.category-card label {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  cursor: pointer;
  padding-left: 52px;
  position: relative;
  min-height: 40px;
  justify-content: center;
}

.category-name {
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--text);
  transition: color var(--transition-base);
}

.category-desc {
  font-size: 0.8125rem;
  color: var(--text);
  opacity: 0.65;
  line-height: 1.5;
  transition: color var(--transition-base);
}

/* ---- Toggle Switch (Pill) inside Card ---- */
.category-card label::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 40px;
  height: 22px;
  background: var(--border);
  border-radius: var(--radius-pill);
  transition: background var(--transition-fast);
}

.category-card label::after {
  content: '';
  position: absolute;
  left: 3px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  background: var(--bg);
  border-radius: 50%;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  transition: transform var(--transition-fast), background var(--transition-base);
}

/* Checked state */
.category-toggle:checked + label::before {
  background: var(--accent);
}

.category-toggle:checked + label::after {
  transform: translateY(-50%) translateX(18px);
}

/* Focus state for accessibility */
.category-toggle:focus-visible + label::before {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ============================================
   TEXT HIGHLIGHTS
   ============================================ */
mark,
.highlight {
  background: var(--highlight);
  border-radius: 2px;
  padding: 0 2px;
  color: inherit;
  transition: background var(--transition-base);
}

/* ============================================
   FOOTER
   ============================================ */
footer {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  text-align: center;
  border-top: 1px solid var(--border);
  margin-top: var(--spacing-xl);
  transition: border-color var(--transition-base);
}

footer a {
  color: var(--accent);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

/* ============================================
   RESPONSIVE BREAKPOINTS
   ============================================ */

/* ---- Tablet (max-width: 768px) ---- */
@media (max-width: 768px) {
  main {
    grid-template-columns: 1fr;
    padding: 0 var(--spacing-md) var(--spacing-lg);
  }

  #editor.two-column {
    grid-template-columns: 1fr;
  }

  header {
    padding: var(--spacing-md) var(--spacing-lg);
    flex-direction: column;
    gap: var(--spacing-sm);
    text-align: center;
  }

  .header-controls {
    flex-direction: column;
    align-items: center;
    width: 100%;
  }

  header h1 {
    font-size: 1.5rem;
  }

  .category-grid {
    grid-template-columns: 1fr;
  }

}

/* ---- Mobile (max-width: 480px) ---- */
@media (max-width: 480px) {
  html {
    font-size: 15px;
  }

  header {
    padding: var(--spacing-md);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
  }

  header h1 {
    font-size: 1.375rem;
  }

  .header-controls {
    flex-wrap: wrap;
    gap: var(--spacing-sm);
  }

  .header-controls .char-limit-controls label {
    font-size: 12px;
  }

  main {
    padding: 0 var(--spacing-md) var(--spacing-md);
    gap: var(--spacing-md);
  }

  textarea#input-text,
  #output-text {
    min-height: 160px;
    padding: var(--spacing-sm);
    font-size: 0.875rem;
  }

  .category-card {
    padding: var(--spacing-sm);
  }

  .category-card label {
    padding-left: 48px;
  }

  #stats-bar {
    padding: var(--spacing-sm);
  }
}

/* ============================================
   REDUCED MOTION
   ============================================ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms;
    animation-iteration-count: 1;
    transition-duration: 0.01ms;
  }

  html {
    scroll-behavior: auto;
  }
}